SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f94d6b02977eb1b0a4dae773515d61f179101bc273f29aec8b221fcf902b333' 
  AND token = 'yRaEZldNbwXtjqhZ49jsSEFPewnSVwPriYlAw0oQSNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}